1. Field of the Invention
The invention relates to a metering device for fuel upstream of an oxidation catalyst in the exhaust gas system of an internal combustion engine.
2. Description of the Prior Art
In modern internal combustion engines, steps are taken that are useful for the regeneration of the exhaust system of the internal combustion engine and for its thermal management. Injection valves for the metered introduction of fuel are used, for example, to regenerate a diesel particulate filter. This does not require provision of a costly coating of the diesel particulate filter or an additive tank for an additive. The device for metering diesel fuel upstream of the oxidation catalytic converter is integrated into the low-pressure fuel circuit. It injects a precisely metered quantity of fuel into the exhaust system upstream of the oxidation catalytic converter without compressed air assistance. This sharply increases the temperature of the exhaust gas in the exhaust system as it flows through the oxidation catalytic converter. This triggers the combustion of particulate matter stored in a particulate filter. The flow rate is varied in accordance with current requirements. The rugged, completely maintenance-free system controls the supply of fuel as needed, independently of the injection system of the engine.